The present invention relates to a flow path switching device which can be suitably applied to a shower unit and the like disposed in a bathroom, etc. and used for washing a human body, etc., and specifically to a flow path switching device applied suitable to a shower unit which can create purified water by adsorbing and decomposing residual chlorine contained in service water, and a shower unit having the same.
For example, as disclosed in JP-A-11-9485, a conventional flow path switching device, which is provided in a shower head and the like of a purified water shower unit and the like, switches a flow path to be selected by closing one flow path among two flow paths by a valve body as well as by opening the other flow path. Namely, the respective two flow paths must be opened/closed simultaneously, thereby making the structure complicated. By this complication in structure, the pressure loss increases, the discharge amount of the shower decreases, and user""s comfortableness may be damaged. Further, because it is very difficult to dispose the complicated mechanism in a limited space in a shower head, the size of a shower head having the conventional flow path switching mechanism becomes large as the whole or partially, thereby injuring its appearance.
Further, a conventional purified water shower unit removing or decomposing residual chlorine contained in service water and having means for switching raw water and purified water, is constructed, for example, as shown in FIG. 5. Purified water shower unit 100 depicted in FIG. 5 has a shower head 101 and a shower grip 102, and raw water is introduced into a switching device 103 and distributed to a purified water flow path xe2x80x9cbxe2x80x9d having therein a filter material 104 and a raw water flow path xe2x80x9caxe2x80x9d bypassing the filter material 104. Raw water or purified water having passed through filter material 104 is led to the head portion, and discharged as shower. Thus, in a conventional purified water shower unit, because flow path switching device 103 is disposed at an upstream side of filter material 104, it is necessary for a user to use both hands in order to switch flow paths as shown in FIG. 6.
Moreover, in the conventional purified water shower unit 100, filter material 104 is formed as a cylindrical shape and raw water flows into the cylindrical filter material 104 from its outer side surface, and by this structure, the inflow cross-sectional area of the filter material 104 is ensured to be large and its flow path resistance is reduced.
In such a purified water shower unit 100 having switching device 103 for switching raw water flow path xe2x80x9caxe2x80x9d and purified water flow path xe2x80x9cbxe2x80x9d, after raw water is introduced into switching device 103, it is distributed to the periphery side and the inner circumferential side of filter material 104 by the switching device 103, and the inner circumferential side is made into the raw water flow path xe2x80x9caxe2x80x9d and the periphery side is made into the purified water flow path xe2x80x9cbxe2x80x9d. When raw water is led to the inner circumferential side, the raw water passes through the inner circumferential side as it is, and introduced into shower head 101 and then discharged as shower water. When raw water is led to the periphery side of filter material 104, the raw water flows from the periphery of the filter material 104 to the inner circumferential side of the filter material 104 to the inner circumferential side of the filter material 104 through the filter material 104, and introduced into shower head 101 and then discharged as purified water shower.
Thus, in the conventional purified water shower unit, since the purified water flow path xe2x80x9cbxe2x80x9d is formed so as to make water flow from the periphery to the inner circumferential side of filter material 104, pressure operates on the filter material 104 in a direction toward the center. Therefore, a reinforcement member 105 for a filter material, such as a cylindrical member made of a porous plastic or a plastic having many holes, is required at the inner circumferential side of the filter material 104.
Namely, in the conventional purified water shower unit 100, because switching device 103 for switching raw water flow path xe2x80x9caxe2x80x9d and purified water flow path xe2x80x9cbxe2x80x9d is disposed at a position upstream of filter material 104 and reinforcement member 105 is required at a center position of the cylindrical filter material 104, when a user switches the flow path during use of the shower, the user has to switch using both hands as shown in FIG. 6, and the shower unit is large in shape by a volume corresponding to the reinforcement member 105, or, the water purification ability thereof is low.
An object of the present invention is to provide a flow path switching device which has a simple structure and can save space, and which can achieve a low pressure loss, and a shower unit equipped with the flow path switching device.
Another object of the present invention is to provide a purified water shower unit having a switching device between a raw water flow path and a purified water flow path, in which the switching operation can be performed by one hand, a shape of a filter material can be sufficiently maintained even if a water pressure is applied to the filter material, and the filter material is efficiently worn off over the whole and the space in the unit can be efficiently used.
To accomplish the above objects, a flow path switching device according to the present invention comprises two flow paths having pressure losses different from each other, and a valve body provided corresponding to one of the two flow paths which has a lower pressure loss, and the two flow paths are switched by opening/closing the flow path having a lower pressure loss with the valve body.
Where, it is preferred that the pressure loss of the flow path with a lower pressure loss is in a range of ⅕ to {fraction (1/20)} of a pressure loss of the other flow path.
A shower unit according to the present invention comprises such a flow path switching device. It is constructed as a shower unit capable of switching between raw water and purified water by providing a filter material in the shower unit.
The shower unit according to the present invention is suitable as a purified water shower unit equipped with a filter material. Namely, a shower unit according to the present invention comprises a cylindrical filter material, a raw water flow path, a purified water flow path, and a flow path switching device constructed so that the raw water flow path and the purified water flow path are switched by opening/closing the raw water flow path.
Particularly, this shower unit may be constructed so that raw water flowing in the purified water flow path flows from inside of the cylindrical filter material toward outside thereof. The purified water flow path may be always opened.
Further, in this shower unit, it is preferred that the flow path switching device is provided at a position downstream of the filter material.
Furthermore, it is preferred that the filter material is formed using a sulfite or an activated carbon, and calcium sulfite is desired as the used sulfite and fibrous activated carbon is desired as the used activated carbon.
Although the filter material is provided in a housing, a part of or the whole of the housing enclosing the filter material may be transparent.
Further, preferably a reinforcement member with a water permeable property is disposed on a periphery of the filter material, more preferably, the reinforcement member with a water permeable property is formed from a nonwoven fabric, and further more preferably, such a reinforcement member with a water permeable property is layered around the periphery of the filter material. Further, it is preferred that a pressure loss due to the reinforcement member with a water permeable property is higher than a pressure loss due to the filter material.
Further, it is preferred that a water permeation resistance of the inflow side of the filter material, that is, a water permeation resistance at a periphery side of the filter material, is greater than a water permeation resistance of the outflow side of the filter material, that is, a water permeation resistance at an inner circumferential side of the filter material.
In the above-described flow path switching device according to the present invention, since two flow paths and a valve body equipped corresponding to one of the two flow paths which has a lower pressure loss are provided and the device is constructed so that the two flow paths are switched by opening/closing the flow path having a lower pressure loss with the valve body, it is not necessary to open/close the two flow paths at the same time, the device may be constructed to be simple in construction and so as to be able to save space as compared with a conventional device, and the pressure loss can be reduced.
When such a flow path switching device is provided in a shower unit, the switching operation of flow paths is easy in spite of a space saving switching device, and a comfortable shower unit capable of achieving a sufficient amount of shower discharge can be realized.
Further, in the above-described purified water shower unit according to the present invention, a filter material is formed as a cylindrical shape, and in both cases of purifying raw water and passing raw water, the raw water is introduced into the inner circumferential side of the cylindrical filter material, an outlet port of the raw water flow path can be provided at the inner circumferential side of the filter material and at a position opposite to an inlet port of the raw water flow path, and an outlet port of the purified water flow path can be provided at the periphery side of the filter material. And, in such a construction, raw water introduced into the purified water flow path is flown from the inner circumferential side of the filter material toward the periphery side thereof, the internal pressure is made as a dominant pressure applied to the filter material, and because the internal pressure applied to the filter material can be supported by the reinforcement member with a water permeable property which is disposed at the periphery side of the filter material, a conventional reinforcement member, which has been required to be provided at an inside position of a cylindrical filter material, basically becomes unnecessary. By using a thin and strong nonwoven fabric and the like for the reinforcement member with a water permeable property provided at the periphery side of the filter material, the capacity occupied by the reinforcement member with a water permeable property can be made smaller than a capacity occupied by a conventional reinforcement member, thereby making the unit small or increasing the amount of the filter material. Therefore, as compared with a conventional unit, a purified water shower unit having a high ability while being made small as a whole can be realized.
Further, by providing means for opening/closing the raw water flow path, that is, the flow path switching device, at a position downstream of the filter material, when the raw water flow path is closed, an opening flow path is only the purified water flow path, and when the raw water flow path is opened, although the purified water flow path is also opened, because there is a pressure loss due to the existence of the filter material in the purified water flow path, the raw water flows selectively through the raw water flow path, and therefore, raw water and purified water can be selectively discharged by the flow path switching device which opens/closes the raw water flow path. Namely, because the switching device can be provided at a position of fingers of a hand of a user holding the shower body, the user can switch between raw water and purified water by one hand.
Further, an appropriate degree of pressure loss can be generated at a position of the reinforcement member with a water permeable property by layering the reinforcement member with a water permeable property on the periphery of the filter material at an appropriate amount, and the flow of the raw water flowing in the filter material can be made uniform and the filter material can be efficiently worn off over the whole by making the pressure loss of the reinforcement member with a water permeable property higher than the pressure loss of the filter material.
Furthermore, in the purified water shower unit according to the present invention, it is also possible to observe and check a flow, a dirt, etc. in the housing by making a part of or the whole of the portion of the housing enclosing the filter material transparent.
Thus, in the present invention, an excellent purified water shower unit can be provided, wherein the switching operation can be performed by one hand, the switching mechanism is a simple structure, the shape of the filter material can be sufficiently maintained even if a water pressure is applied to the filter material, and the filter material is worn off efficiently over the whole and the space in the unit is efficiently used.